Dynamic and Static Aging Precipitation of β-Mg_(17)Al_(12) in the AZ80 Magnesium Alloy During Multi-directional Forging and Subsequent Aging

摘要

Dynamic and static aging precipitation of Mg_(17)Al_(12) phases in AZ80 magnesium alloy was studied by multidirectional forging(MDF) with decreasing temperatures from 410 to 300 ℃ and subsequent aging process. The results show that the morphology of the β-Mg_(17)Al_(12) phases during forging process dynamically precipitates and aging process(statically precipitation) exhibited granular and laminar shapes, respectively. During the MDF, the inhomogeneous dynamic precipitation of the β-Mg_(17)Al_(12) phases results in the uniformity on grain size, which is fine in the area with many granular Mg_(17)Al_(12) phases but the grain is still coarse where there is no Mg_(17)Al_(12) phases. During the aging process, the morphology of newly formed β-Mg_(17)Al_(12) phases depends on the structural character of the forged sample. The newly precipitated β-Mg_(17)Al_(12) phases are coarse laminar and needle-like shape in area with coarse grain. While, the fine newly precipitated β-Mg_(17)Al_(12) phases are fine granular and needle-like in the area with fine grain.